1. Field of the Invention
The present invention relates to a transparent display apparatus and a method for controlling the same, and more particularly, to a transparent display apparatus and a method for reducing light interference to improve visibility of images displayed on the transparent display apparatus.
2. Description of the Related Art
A transparent display apparatus allows a user to see objects placed behind the display device while viewing the image displayed by the display device. Although there have been attempts to provide transparent display device with a liquid-crystal display (LCD), the two polarizing plates included in the LCD display significantly reduces the light transmittance rate through the display device. Accordingly, it is extremely difficult to implement transparent display apparatus with LCD based display device.
Display devices employing organic light-emitting diode (OLED) do not require such polarizing plates as the LCD display device. For this reason, the OLED based display device has been considered as the promising component in implementing a transparent display apparatus.
Such a transparent display apparatus can be applied as a front glass for a vehicle or as a smart window for a house for displaying information while allowing the user to view the outside environment through the transparent display.
In this case, however, the visibility of the information displayed on the transparent display apparatus is often degraded by certain degree depending on the brightness of the environment. More specifically, it becomes difficult for the user to see the image on the display device when the external light at entering from the rear side of the transparent display apparatus is excessively brighter than the light emitted from the display device. More specifically, it becomes difficult for the user to recognize the information displayed on the transparent display device when the external light entering from the rear side of the display apparatus is excessively brighter than the light emitted from the display device itself.
Attempts have been made to solve the aforementioned problem by shielding the external light entering from the rear side of the entire transparent display apparatus. This method, however, prevents the user to see the outside environment through the display device, significantly limiting the user experience in using the transparent display device, thereby defeating the purpose of having the transparent display apparatus.
Accordingly, there remains a need for a transparent display device capable of maintaining both the visibility of the displayed image as well as the transparency of the display device.